Answer : 4. "महालनोबिस का जन्म 1983 में कलकत्ता में हुआ था।"
Explanation :

About Prof. Prasanta Chandra Mahalanobis : 

He was known as the “Father of Indian Statistics”. 

He was born on 29th June 1893 in Calcutta. 

He was awarded the Padma Vibhushan in 1968 for his contribution to science and services 

He established the Indian Statistical Institute in 1931. 

He started the journal Sankhya. 

He is known as the architect of Indian planning. 

India celebrates June 29th as National Statistics Day to recognize the contribution of statistics in daily life and to educate the general public on the importance of statistics in socio-economic planning and policy formulation. The first National Statistics Day was celebrated on 29th June 2007.